The greatest thing about baseball, perhaps, is its history. In nearly 150 years of play in leagues and informal competition that goes back further, many people have made baseball’s history what it is today.

It's not just players, but top executives, media members and even Supreme Court jurists helping craft baseball’s story.

Here are the 40 people who have done the most to shape Major League Baseball.

40. Theo Epstein

The scary thing about Epstein? At 42, he might only be just beginning, with a long baseball career in front of him. What Epstein, SN's 2016 MLB Executive of the Year, accomplishes over the next two to three decades could vault him further up this list. Being the driving force to end epic World Series droughts for the Boston Red Sox and Chicago Cubs and helping redefine the value of a good baseball front office executive gets him on it.

39. Bill Doak

Through the early 20th century, baseball players used gloves only slightly larger than their hands. Doak, who pitched 16 seasons in the majors between 1912 and 1929, helped create the modern glove. As noted in his Society for American Baseball Research biography, Doak approached the Rawlings Sportings Good Co. of St. Louis in 1919, suggesting a glove with webbing between the thumb and first finger. The glove Doak helped design remained in use for three decades and the general concept can be seen in baseball to this day.

38. Melissa Ludtke

During the 1977 World Series, MLB commissioner Bowie Kuhn overruled a vote by the Los Angeles Dodgers allowing locker room access to Ludtke, a Sports Illustrated reporter. Her magazine’s subsequent successful lawsuit, in which Ludkte was a named plaintiff, granted female reporters clubhouse access and broadened media access in general. Ludtke wrote in a 1990 Los Angeles Times retrospective that since the suit, nearly all professional teams have “decided to grant unlimited locker room access.”

37. Hideo Nomo

Nomo had gone 78-46 with a 3.15 ERA in five seasons in Japan when the 26-year-old abruptly retired after the 1994 season. His ploy? Become the first Japanese player in decades to play Major League Baseball. Unlike Masanori Murakami, who played two seasons with the San Francisco Giants in the mid-1960s before returning to Japan for another 17 years, Nomo became a star in the states and helped usher in a new generation of Japanese standouts in the majors, such as Ichiro Suzuki, Hideki Matsui and Yu Darvish.

36. Curt Flood

Flood didn’t topple the Reserve Clause when he refused to report to the Philadelphia Phillies after a December 1969 trade from the St. Louis Cardinals. The Supreme Court denied Flood’s subsequent lawsuit against baseball in 1972. His case set no precedent, played no role in arbitrator Peter Seitz abrogating the clause in 1975 and creating free agency. Neutral arbitration and Marvin Miller’s push for it after he became executive director of the Major League Baseball Players Association in 1966 spurred free agency, not Curt Flood.

That said, Flood’s courage to take on the collusive baseball establishment of the late 1960s, as a black man no less at a time of intense racial unrest in America, makes him one of the greatest symbols in baseball history, if nothing else. The story of baseball’s labor history can’t be told without Flood’s chapter.

35. Mark McGwire

Say what you will about steroids. McGwire and Chicago Cubs outfielder Sammy Sosa’s chase of Roger Maris’s home run record throughout the 1998 season helped reinvigorate lagging fan interest after the 1994 strike. Scott Lindholm noted for Beyond the Box Score in 2014 that average attendance had dropped to about 25,000 per game in 1995. By 2000, it was back to pre-strike levels of around 30,000 per game.

34. Robert Bowman

Like Epstein, Bowman could rise on this list in the years to come. As president and CEO of MLB Advanced Media, Bowman leads a number of evolving efforts for the game. His company’s products include MLB.com, MLB Network (which it manages for owner, MLB), and its At Bat mobile app. More than this, Bowman helps symbolize the greatest agent for change in the sport in recent years: broadcast dollars, which have helped push Major League Baseball’s cumulative revenue from roughly $2 billion in 1992 to approximately $9.5 billion today, according to Forbes.

33. Roy Hofheinz

In the mid-1960s, Houston Astros owner Roy Hofheinz built his team the Astrodome, the so-called eighth wonder of the world. One problem: Grass underneath the clear, geodesic dome roof soon died. So Hofheinz settled on a new, heretofore unused technology in baseball, Astroturf. By the mid 1970s, a significant number of MLB teams had co-opted the innovation, helping usher in an era of fast play with many stolen bases.

32. Lefty O'Doul

Like Babe Ruth, O’Doul began as a pitcher before becoming one of the greatest hitters in the game. He also had a long career as a Pacific Coast League manager with the San Francisco Seals, tutoring hitters such as Joe and Dom DiMaggio. Here’s the reason O’Doul makes this list: Late in his playing career, he participated in a postseason tour of Japan. He stuck around after and helped establish professional baseball in Japan. The father of Japanese baseball and perhaps the game’s greatest ambassador aside from Buck O’Neil, O’Doul made numerous goodwill trips to Japan, both before and after World War II.

31. Tony La Russa

La Russa might be the greatest manager in baseball history, though John McGraw, Casey Stengel and Earl Weaver among others have arguments for this title, and they don’t crack this list. What gets La Russa a mention here is his pioneering use of specialist relief pitchers, beginning around 1990 with the Oakland Athletics. It was perhaps the most profound tactical shift in baseball in years, and the effects of La Russa’s innovation continue to be felt in the game.

30. David Neft

Neft led the most ambitious and significant baseball research undertaking to that point (and arguably since) in the 1960s, when his company, Information Concepts Inc., went library to library across the country to compile a true statistical record of the game. As Alan Schwarz wrote in "The Numbers Game," baseball had an incomplete and uncertain statistical history to this point, and varied depending on who was telling it. The sum of Neft’s team’s efforts, "The Official Baseball Encyclopedia," debuted in 1969.

29. Ted Williams

Baseball’s last .400 hitter influenced later generations of hitters with his 1971 publication of “The Science of Hitting.” His greatest impact, arguably, came July 25, 1966, when he gave his Hall of Fame induction speech. Williams spoke briefly, in deference to the other honoree on-stage with him, 75-year-old Casey Stengel. But Williams still managed to effect change, saying toward the end of his short speech, “I hope that some day Satchel Paige and Josh Gibson will be voted into the Hall of Fame as symbols of the great Negro Players who are not here only because they weren’t given the chance.” Negro League inductions began five years later.

28. Alexander Cleland

Even in the early 20th century, baseball writers and fans had the idea of a Hall of Fame, perhaps inspired by the Hall of Fame for Great Americans, which opened in 1901 in New York City. As Bill James wrote in "Whatever Happened to the Hall of Fame?", writers would make proclamations in long-ago news stories that players had “entered the Hall of Fame” with their performance in some key game. But it took until 1934 when Cleland, a Scottish businessman, got the idea for a baseball museum while watching workers expand Doubleday Field in Cooperstown, the game’s mythical birthplace. With help from others, the greatest shrine in American sports opened five years later.

27. Barney Dreyfuss

For at least a year, beginning in mid-1902, Pittsburgh Pirates owner Barney Dreyfuss pushed for a postseason challenge between the National and upstart American leagues. “I’ll tell you what I’ll do,” Dreyfuss told the Evening Star of Washington, D.C. in June 1902. “I will wager $5,000 on a series of ten games between the Pittsburgh team, if it wins the pennant, and the winner of the American League championship. We will play the winning team, or a picked team, but probably a regular team would play better ball. I think ten games would be a fair number to play, five games to each city.”

Dreyfuss kept making public entreaties over the next year, repeatedly mentioning the gambling possibilities of postseason play. Finally, near the end of the 1903 season, he and Boston Americans owner Frank Killilea agreed to play the first World Series.

26. Oliver Wendell Holmes Jr.

According to John Helyar’s classic, "Lords of the Realm," baseball’s Reserve Clause dated to 1879, when the eight pro teams at the time opted to “reserve” five of their players apiece each year, preventing high salaries and free agency. The arrangement soon drew heated opposition, including in 1915 when owners of the short-lived Federal League brought an anti-trust suit against the National League. The United States Supreme Court unanimously denied the suit in 1922, with Associate Justice Holmes writing in the majority opinion that baseball wasn’t interstate commerce and thus not covered by anti-trust laws. Free agency didn’t come to baseball until the 1970s.

25. Happy Chandler

Kenesaw Mountain Landis played a significant role in keeping baseball segregated during his 25 years as commissioner. If a likeminded successor had followed him after his death in 1944, perhaps Jackie Robinson wouldn’t have broken baseball’s color barrier three years later. But Happy Chandler, a former Kentucky senator, had more progressive views than his predecessor and didn’t intervene or cowtow to owners, who had voted 15-1 against the signing. Robinson got his rightful spot with the Dodgers. The spurned owners ousted Chandler in 1951.

24. Connie Mack

The record books will show Mack as having the most losses of any manager in baseball history, partly due to the Great Depression wiping out his last pennant-winning team and also due to Mack sticking around the Philadelphia Athletics dugout another decade after the economy recovered. Had he left the dugout at 70 rather than 87, he might be remembered more for what he was through the early 1930s: a towering figure in early 20th century baseball and one of its finest managers, crafting two of its greatest dynasties and helping the American League establish itself.

23. Willie Mays

There aren’t a ton of players on this list. The definition of “most important” is somewhat broad here, though it mostly covers people who impacted the game and did more than simply excel on the playing field. Ty Cobb doesn’t make this list, nor does Joe DiMaggio nor Barry Bonds and many other legends. So why’s the Say Hey Kid here? Aside from being arguably the greatest player in baseball history and making one of its most memorable catches in the 1954 World Series, Mays inspired a generation of African-Americans to play ball. Their numbers peaked in baseball in the decade after he retired and are a fraction today of what they once were. Baseball could use another Willie Mays.

22. Pete Rose

All-time hit king. Supreme example to players and managers of why to never, ever bet on the game. Banned for life though he somehow remains an ubiqitous presence around baseball.

21. Shoeless Joe Jackson

Similar to Rose, Jackson’s an example of what not to do for ballplayers, albeit on a slightly larger scale. In conspiring with seven Chicago White Sox teammates to throw the 1919 World Series, Jackson nearly broke the game. He remains a conflicted figure nearly a century later. While Jackson admitted twice in court that he accepted $5,000 in gamblers’ money, he hit .375 in the series and hit its only home run. In a sense, he’s one of the most tragic figures in baseball history.

20. Dr. James Andrews

If any doctor is credited as a baseball legend these days, it’s generally Dr. Frank Jobe, whose development of Tommy John surgery in 1974 has saved countless arms since. Dr. Andrews’ development of arthoscopic surgery around the same time has been somewhat less heralded, though also critically important for keeping more young pitchers in the game.

19. Roberto Clemente

Had Clemente merely been a splendid player — a superb outfielder and maybe the best contact hitter of the 1960s, with underrated longevity — he wouldn’t have made this list. But when Clemente died on a plane trip to Nicaragua on New Year's Eve in 1972 to bring relief supplies to survivors of an earthquake, he solidified his status as baseball’s greatest humanitarian. MLB’s annual sportsmanship award is named for him today.

18. Buck O'Neil

Maybe the greatest injustice with Cooperstown in recent years came when it closed the door on Negro League inductions in 2006. Thankfully, the Hall of Fame’s board of directors changed the rules for its veterans voting again in July, allowing Negro Leaguers to be considered once every 10 years. Under this setup, O’Neil won’t be eligible for consideration until fall 2020. But the door’s at least open again for baseball’s greatest ambassador and Negro Leagues supporter.

17. Doc Adams

“You forgot Alexander Cartwright!” some reader is going to say after reading this list. Cartwright’s absence is intentional here because of the glaring inaccuracies on his Hall of Fame plaque, such as him supposedly setting the distance of 90 feet between bases. At some point, perhaps the Hall of Fame can amend Cartwright’s plaque and give credit to Adams, the person who might have actually set base distances.

Adams, who also invented the position of shortstop, never claimed to be baseball’s father. “It jest growed,” he told an interviewer late in life. When baseball needed a more marketable origin story, first Abner Doubleday and then Cartwright benefited, while Adams and a few others were forgotten. Major League Baseball Official Historian John Thorn has done much to bring Adams and company back to light in recent years.

16. Lou Gehrig

Gehrig set one of the greatest records in baseball history, playing 2,130 consecutive games while establishing himself as maybe the top first baseman of all-time. Then, after taking terminally ill early in the 1939 season with career-ending amyotrophic lateral sclerosis, Gehrig gave perhaps the finest speech the game’s ever seen. “Today, I consider myself the luckiest man on the face of the earth.” One would be challenged to find more famous words ever said on a baseball field.

15. Hank Aaron

Aaron battled through a torrent of racist hate mail and death threats as he chased baseball’s most hallowed record, Babe Ruth’s 714 home runs, through the summer of 1973 and early 1974. Barry Bonds has since broken Aaron’s record, which ran to 755 home runs, but the spirit and courage of the Atlanta Braves great will never be forgotten. Less-remembered: Aaron also had a hand in getting Frank Robinson hired as MLB’s first black manager (not counting Buck O’Neil’s job in the Chicago Cubs’ so-called college of coaches in 1962). Aaron called for MLB to have a black manager nine days before the Cleveland Indians hired Robinson in 1974.

14. Dr. Frank Jobe

As of this writing, 141 pitchers have had the practice Dr. Jobe originated in 1974 when he reconstructed Tommy John’s ulnar collateral ligament. Dr. Jobe enabled John to pitch another 15 years in the majors. In 2015, John Smoltz became the first pitcher who’s had the surgery to be inducted into the Hall of Fame. Perhaps at some point, Dr. Jobe’s induction can follow.

13. Bill James

How did the former night watchman at a pork and beans factory finish in front of Willie Mays and Lou Gehrig here? James used those shifts in the mid-1970s to work on baseball research. This research later became the basis for a series of successful books and a cornerstone for sabermetrics. With the help of Ballentine Books, James did as much anyone to bring sabermetrics into the mainstream, even coining the phrase in 1982. His handiwork has also done much to reshape the game, helping the Boston Red Sox and Chicago Cubs end those long World Series dry spells for one.

12. Walter O'Malley

With the evolution of transcontinental air travel in the middle of the 20th century, westward expansion was probably going to happen in baseball at some point. It took O’Malley to jumpstart the process and transform the baseball landscape in 1958, when he took his Dodgers from Brooklyn to Los Angeles and motivated Horace Stoneham to take the Giants from New York to San Francisco. O’Malley might rank as one of the top five most reviled figures in baseball history. But he absolutely deserves a spot on this list.

11. Bud Selig

Sure, baseball’s commissioner emeritus has all the charisma of a series of insurance documents. He might also be the greatest commissioner in baseball history. Next to Kenesaw Mountain Landis, Selig was certainly the most influential. From the time the Milwaukee Brewers owner became acting commissioner in 1992 to when he stepped down from the permanent position in 2015, revenue for baseball grew from roughly $2 billion to approximately $9 billion. He could go in the Hall of Fame in a few weeks.

10. Henry Chadwick

The Bill James of the 19th century, Chadwick created a number of early baseball statistics that, somehow, remain benchmarks in the game today. Aside from inventing batting average and earned run average, he also created the box score, "K" for strikeouts, and the system of assigning numbers based on defensive positions. In a sense, Chadwick might have done as much as any 19th century figure to spread the popularity of the game, helping make it transmittable through newspapers.

9. Rube Foster

Black baseball existed before Foster, with greats such as John Donaldson starring in semi-pro and barnstorming circuits around the Midwest in the 1910s. Some African-Americans such as Bud Fowler even played in the majors during Reconstruction before the “gentleman’s agreement” of the 1880s drove blacks from the game. Foster gave black players their own league when he spearheaded the formation of the Negro National League in 1920. The father of organized black baseball lived just 10 more years before dying young, but it was long enough to see a wave of black superstars such as Satchel Paige and Cool Papa Bell enter the game.

8. William Hulbert

For every egregiously bad Hall of Fame selection by committee, there’s been one like Hulbert which can justify having a veteran voting structure in place to rediscover lost legends. The Veterans Committee inducted Hulbert in 1995, more than a century after his 1882 death at 49. Hulbert worked in baseball for barely a decade, but it came during a pivotal stretch. He started by purchasing three shares of the Chicago White Stocking Ball Club of the old National Association before the 1871 season, according to his SABR bio. Drunkeness plagued the NA, and it soon found itself on the verge of collapse. With help from player (and later sporting good magnate) Al Spalding, player/manager Harry Wright, and Chicago Tribune sports editor Lewis Meacham, Hulbert founded the National League in 1876.

7. Albert Spalding

First, Spalding was one of baseball’s greatest players, going 204-53 with a 2.21 ERA for the Boston Red Stockings of the National Association from 1871 through 1875, according to Baseball-Reference.com. Then, Spalding assisted William Hulbert in founding the National League in 1876. Later, he became a sporting goods magnate, organized an 1888 world tour for baseball, and, most notoriously, helped organize the 1905 Mills Commission, which named Abner Doubleday baseball’s founder.

6. Marvin Miller

The highest non-Hall of Famer on this list, Miller helped reshape the national pastime’s landscape in two decades as executive director of the Major League Baseball Players Association. His push for collective bargaining, which began in MLB two years into his tenure, led to the players winning neutral arbitration in the 1970 collective bargaining agreement. This led to arbitrator Peter Seitz abrogating the Reserve Clause in 1975 and creating free agency. Baseball is more equitable and fairer to players thanks to Miller’s efforts. Whether spurned managers and executives ever let him into Cooperstown is another story.

5. Branch Rickey

After Rickey became president of the St. Louis Cardinals, he learned a hard baseball truth: There was no way his team could compete financially with larger clubs to buy the most expensive players. So he created baseball’s modern farm system to develop his own stars, such as Stan Musial, who began in the minors as a pitcher. Later, as president and general manager of the Brooklyn Dodgers, Rickey accessed an even greater source of untapped talent, signing Jackie Robinson as baseball’s first black player in the modern era. Not finished, Rickey also helped bring sabermetrics into front offices and helped spur baseball’s westward expansion with his involvement with the Continental League in the late 1950s.

4. Ban Johnson

Because the National League has enjoyed an exemption to anti-trust laws for much of its existence, nearly every league to ever challenge its monopoly has met a quick demise. Just look at the sad fate of the Players League of 1890, the Federal League of 1915-16 or the ill-fated Continental League. Only one challenger has achieved success: Johnson, who transformed the minor Western League into the American League in 1901 and then led it through two years of open war with baseball’s senior circuit. When the dust settled, baseball had its present two-league structure.

3. Kenesaw Mountain Landis

After the American League solidified itself, a three-man commission ruled the game, weakly enforcing judgment and letting gambling run rampant through baseball. In the wake of the 1919 World Series, baseball needed a strong man to rid the game of gambling. The owners got their man in federal judge Kenesaw Mountain Landis, who quickly banned the Black Sox and a number of other players who’d sold games or even written of wanting to do so. Landis ruled with an iron fist, perhaps too strong of one, and also did much to keep the game segregated through his death in 1944. But his impact on baseball can’t be denied.

2. Jackie Robinson

Integration probably wasn’t far off in baseball in 1947, with the Civil Rights Movement kicking into high gear in the following two decades and integrating most every facet of American life from buses to schools to the real estate market. Still, baseball might have lacked black players another 10-15 years, if not longer, had Robinson not broken modern baseball’s color barrier with triumphant stoicism. Hank Aaron, Willie Mays, Bob Gibson and so many other black stars in those years owe their MLB careers to Robinson. And every year, the anniversary of April 15, 1947, reminds MLB to reassess its diversity efforts.

1. Babe Ruth

Baseball’s greatest hero rose to prominence right when it needed him most. Ruth, who’d debuted as a pitcher with the Boston Red Sox in 1914 before becoming a full-time position player midway through the 1918 season, helped baseball recover after the tainted 1919 World Series. Ruth rewrote the record books for home runs, became baseball’s first marketing icon, and to this day arguably remains its top player. As I wrote when I had readers vote on the 25 most important people in baseball history in 2014, it’s difficult to overstate Ruth’s significance to the sport. This remains true.